People Scot might not like trashing his glen (7)
I believe the answer is:
english
'people scot might not like trashing his glen' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'trashing his glen' is the wordplay.
'trashing' indicates anagramming the letters (I've seen 'trash' mean this).
'his'+'glen'='hisglen'
'hisglen' anagrammed gives 'ENGLISH'.
Can you help me to learn more?
(Other definitions for english that I've seen before include "An official language of the Republic of India" , "Common language" , "- rose; - breakfast" , "Language of the shingle?" , "speech" .)